Patent GB-760279-A (GB)
Title: Improvements relating to the treatment of acidic ore pulps and acidic suspensions ofminerals
IPC: C09K23/52
Filed: 1954-07-23
Abstract: A process of facilitating the dewatering of acidic aqueous suspensions of finely divided minerals having a pH not greater than 4 comprises subjecting them to the action of from 0.001 lb./ton to 10 lbs./ton of suspended solids of an acrylic polymer having at least 50 per cent of the monomer units attached to amide groups, the polymer having an average molecular weight of at least 10,000.  Preferred polymers are: polyacrylamides of low, medium and high viscosities or molecular weight ranges, copolymers of acrylamide and acrylic acid, acid - hydrolysed polyacrylonitriles and alkali-hydrolysed polyacrylamides. Copolymers of acrylamide and acrylonitrile, of acrylamide and butyl acrylate, and the like, may also be used.  The preferred addition is from 0.01 to 5 lbs./ton of suspended solids. The addition may be made prior to or during settling, thickening or filtration.  A complex of a co-polymer may be formed by addition thereto of inorganic heavy metal ions, provided the complex is water-dispersible.  Other flocculating materials such as colloids and electrolytes may be used at the same time.  Settling-rate and/or filtration-rate tests were conducted on ore, coal, sand and oreresidue suspensions and on electrolytic refinery sludge.ALSO:A process of facilitating the dewatering of acidic aqueous suspensions of finely divided minerals having a pH not greater than 4 comprises subjecting them to the action of from 0,001 lb./ton to 10 lbs./ton of suspended solids of an acrylic polymer having at least 50 per cent of the monomer units attached to amide groups, the polymer having an average molecular weight of at least 10,000.  Preferred polymers are: polyacrylamides of low, medium and high viscosities or molecular weight ranges, copolymers of acrylamide and acrylic acid, acid-hydrolysed polyacrylonitriles and alkalihydrolysed polyacrylamides.  Co-polymers of acrylamide and acrylonitrile, of acrylamide and butyl acrylate, and the like, may also be used.  The preferred addition is from 0,01 to 5 lbs./ton of suspended solids. The addition may be made prior to or during settling, thickening or filtration.  A complex of a co-polymer may be formed by addition thereto of inorganic heavy metal ions, provided the complex is water-dispersible.  Other flocculating materials such as colloids and electrolytes may be used at the same time.  Settling-rate and/or filtration-rate tests were conducted on ore, coal, sand and ore-residue suspensions and on electrolytic refinery sludge.ALSO:A process of facilitating the dewatering of acidic aqueous suspensions of finely divided minerals having a pH not greater than 4 comprises subjecting them to the action of from 0.001 lb./ton to 10 lbs./ton of suspended solids of an acrylic polymer having at least 50 per cent of the monomer units attached to amide groups, the polymer having an average molecular weight of at least 10,000.  Preferred polymers are: polyacrylamides of low, medium and high viscosities or molecular weight ranges, copolymers of acrylamide and acrylic acid. acid - hydrolysed polyacrylonitriles and alkali-hydrolysed polyacrylamides. Copolymers of acrylamide and acrylonitrile, of acrylamide and butyl acrylate, and the like, may also be used.  The preferred addition is from 0.01 to 5 lbs./ton of suspended solids.  The addition may be made prior to or during settling, thickening or filtration.  A complex of a co-polymer may be formed by addition thereto of inorganic heavy metal ions, provided the complex is water-dispersible.  Other flocculating materials such as colloids and electrolytes may be used at the same time.  Settling-rate and/or filtration-rate tests were conducted on ore, coal, sand and ore-residue suspensions and on electrolytic refinery sludge.